1. Field of the Invention
The present invention relates to a pet waste absorption sheet intended to be spread on a floor, a bottom face of a tray-type pet toilet, or the like.
2. Description of the Related Art
Typically, pet waste absorption sheets have a liquid-impermeable backsheet on a lower surface side, a liquid-permeable topsheet on an upper surface side, and an absorbent core disposed between the backsheet and the topsheet. Such pet waste absorption sheets are intended to be spread on a floor or the like with the lower surface directed downward, so that pets can step on the upper surface of the pet waste absorption sheet.
In a pet mat disclosed in Japanese Unexamined Patent Application Publication No. 2004-187597, the backsheet is a nonwoven fabric laminated with a waterproof film. The absorbent core, which lies on the backsheet, is a pulp layer covered with water absorbent polymer and further wrapped in a carrier tissue. The topsheet, which covers the upper surface of the absorbent core, is a nonwoven fabric that is bonded to the absorbent core by melting a hot-melt sheet interposed between the nonwoven fabric and the absorbent core.
Since the topsheet of JP2004-187597 is a nonwoven fabric, pet claws are liable to catch in fibers of the nonwoven fabric. This may cause a problem that the pet mat will be moved out of position by motion of the pet. In addition, the nonwoven fabric is unsuitable for the topsheet, because the nonwoven fabric tends to feel wet after absorption of urine discharged from the pet.
In pet mats of this type, the topsheet and the absorbent core are preferably bonded to and kept in contact with each other so that liquid applied to the topsheet can readily migrate to the absorbent core. In JP2004-187597, therefore, the topsheet and the absorbent core are bonded to each other by melting the hot-melt sheet. However, this hot-melt tends to interfere with migration of liquid from the topsheet to the absorbent core, which results in leaving urine on the topsheet.
Alternatively, the topsheet and the absorbent core may be bonded to each other by spraying a hot-melt type adhesive over the topsheet or the absorbent core. In this case, however, the adhesive after curing takes the form of fibers and prevents passage of liquid through the nonwoven fabric, which interferes with migration of urine from the topsheet to the absorbent core.